Portable trailer stabilizers

ABSTRACT

A portable trailer stabilizer, comprising: (i) a support surface engagement element configured to selectively engage a support surface; (ii) a trailer engagement element configured to selectively engage a forward end portion of a trailer; (iii) a hydraulic cylinder operatively connected between the support surface engagement element and the trailer engagement element, the hydraulic cylinder configured to extend the trailer engagement element relative to the support surface engagement element; (iv) an on-board, self-contained energy source comprising a hydraulic accumulator operatively coupled to the hydraulic cylinder; (v) an isolation valve fluidically interposing the hydraulic cylinder and the hydraulic accumulator; (vi) a positioning element engagement element configured to selectively couple with a trailer stabilizer positioning element of a tractor; and (vii) a valve operator mechanism configured to (a) open the isolation valve when the when the positioning element engagement element is coupled to the trailer stabilizer positioning element of the tractor, and (b) shut the isolation valve when the positioning element engagement element is uncoupled from the trailer stabilizer positioning element of the tractor, where the hydraulic cylinder, the hydraulic accumulator, and the isolation valve are operatively connected in a closed hydraulic system containing a hydraulic fluid.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication 63/303,393, filed Jan. 26, 2022, and U.S. Provisional PatentApplication 63/188,482, filed May 14, 2021, which are incorporated byreference.

INTRODUCTION

The present disclosure is directed to supporting devices utilized tostabilize and/or support parked trailers and, more particularly, toportable trailer stabilizers that may be used, for example, withsemi-trailers parked at loading docks while loading and/or unloadingcargo, and related methods.

The present disclosure contemplates that distribution warehouses andfacilities having semi-trailer loading/unloading capabilities (e.g.,facilities with loading/unloading docks) are a necessary component ofcommerce in the twenty-first century. These warehouses may act asclearinghouses for shipments from various product suppliers andcentralize the distribution of goods. Large chain retailers utilizewarehouses to generate shipments to particular points of sale that arespecific to the needs of consumers in that area, without requiring theoriginal manufacturer of the goods to identify consumer demand at eachpoint of sale and correspondingly deliver the particular goods to eachpoint of sale.

The present disclosure contemplates that an example distributionwarehouse (or similar facility) may include fifteen or more loading dockbays, with each loading dock bay adapted to receive a single freighttrailer of a semi-truck. A loading dock door selectively closes off anopening of the loading dock bay elevated above ground level (e.g., amezzanine) matching a height of the floor of the freight trailer.Alternatively, for liquid contents of a semi-trailer, a loading dock maycomprise a horizontal or angled floor teamed with piping to allow egressof liquids to and from the semi-trailer. In the context of a warehouse,the relatively equal height between the floor of the loading dock andthe floor of the trailer enables lift trucks (e.g., forklifts) and othermaterial handling devices to move freely back and forth between thewarehouse and interior of the freight trailer.

The present disclosure contemplates that in an example sequence, aloading dock bay at a warehouse or similar facility is initiallyunoccupied by a freight trailer. Thereafter, a semi-trailer driver orterminal tractor driver (or autonomous vehicle) backs a semi-trailerinto alignment with the loading dock bay. In the context of a boxsemi-trailer, this includes backing the rear of the trailer to overlapwith the loading dock door. After the semi-trailer is properly alignedand positioned adjacent to the loading dock door, engagement between theterminal truck and trailer will be continued or discontinued, wherediscontinuing allows the truck or autonomous vehicle to engage anothertrailer and/or relocate to a different location. As used herein, theterm “terminal tractor” includes manned and autonomous vehicles utilizedto engage and reposition semi-trailers. In the context of terminaltractors, a usual practice is to maintain engagement between such avehicle and the freight trailer only long enough to position orreposition the freight trailer with respect to the loading dock bay. Inan example day, a terminal tractor may connect to and disconnect fromone hundred or more freight trailers.

The present disclosure contemplates that, in summary fashion, a terminaltractor (also known as a spotter truck or yard truck) is a dedicatedtractor that stays at the dock facility and is only used to repositionfreight trailers (e.g., not to tow the trailers on the open highways).By way of example, a facility may have ten loading dock bays, but mayhave fifty trailers waiting to be unloaded and/or unloaded. In order toexpedite unloading and loading of contents with respect to eachsemi-trailer, as well as the convenience of the semi-truck drivers thatdeliver to or pick up the trailers from the facility, the trailers mayneed to be shuffled. This means that trailers do not include dedicatedsemi-tractors continuously connected to them. Instead, because nosemi-tractor is connected to many, if not all, of the trailers at afacility, a terminal tractor may be used to shuffle the trailers at thefacility.

The present disclosure contemplates that an exemplary process forengaging between the terminal tractor and the freight trailer includesbacking the terminal tractor under a front end of the semi-trailer so ahydraulic fifth wheel of the terminal tractor engages a king pin of thesemi-trailer, followed by initially raising the hydraulic fifth wheel toraise the front end of the trailer above its normal ride height. Whilethe front end is raised, the landing gear of the freight trailer, whichcomprises a pair of equal length jacks permanently mounted to thetrailer, are also elevated off the ground to allow repositioning of thetrailer via its rear axle(s) engaged with the ground. The hydraulicfifth wheel allows the terminal tractor to reposition trailers withoutever adjusting or otherwise repositioning the trailer's landing gear. Asis customary, associated pneumatic and electrical connections betweenthe terminal tractor and trailer are connected so that the brakes of thetrailer are able to be unlocked. Conversely, to disengage the terminaltractor from the trailer, the hydraulic fifth wheel may be lowered sothat lowering of the fifth wheel is operative to lower the front of thetrailer and contact the ground with the landing gear. When the traileris set down on its landing gear, the trailer is freestanding. After thetrailer is freestanding, associated pneumatic and electrical connectionsbetween the terminal tractor and trailer are disconnected so that thebrakes of the trailer are locked. Thereafter, the terminal tractor pullsout from under the front of the trailer, thereby leaving the traileradjacent to the loading dock door and being supported at the front endusing only the trailer's landing gear.

The present disclosure contemplates that when loading and unloadingcontents from a freestanding trailer, movement of the contentsthemselves and/or a lift truck along the floor of the trailer can impartconsiderable motion to the trailer. While some movement of the traileris inevitable, considerable movement can result in the trailer becomingseparated from the dock and/or possibly tipping over. More importantly,the landing gear of the trailer are generally not designed to hold upthe weight of a fully loaded trailer, let alone the dynamic forcesgenerated by contents and a lift truck moving through a trailer. Incases where these forces are great enough, the landing gear of thetrailer can fail, leading the front end of the trailer to collapse ortip over. The obvious implications of a trailer collapsing or tippingover include damage to the goods within the trailer, the trailer itself,and the lift truck, not to mention the possible serious injury to ordeath of the lift truck operator.

While known devices have been used to support parked semi-trailers,there is a need in the industry for improved trailer stabilizers for usewith parked semi-trailers. In addition, there is a need in the industryfor a trailer stabilizer that utilizes a closed hydraulic system topotentially support the freight trailer. Moreover, there is a need inthe industry for a trailer stabilizer that utilizes a closed hydraulicsystem that can be repositioned underneath a parked semi-trailer andoperates to support the semi-trailer if the landing gear of the trailerfail. Further, there is a need in the industry to provide a trailerstabilizer that may be repositioned by engaging the front of a terminaltractor and deployed by the terminal tractor driving forward and towarda front of the semi-trailer, rather than backing the terminal tractor toreposition a trailer stabilizer. Still further, there is a need in theindustry to provide a trailer stabilizer that can support the weight ofa fully loaded front end of a semi-trailer, upon landing gear failure,that dampens the abrupt forces otherwise present from an undampenedcollision between the semi-trailer and a stabilizer.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a simplified schematic view of an example portable trailerstabilizer system, according to at least some aspects of the presentdisclosure.

FIG. 2 is a schematic view of an example towable portable trailerstabilizer engaged with a trailer, according to at least some aspects ofthe present disclosure.

FIG. 3 is a front elevated perspective views showing various aspects ofan example portable trailer stabilizer according to at least someaspects of the present disclosure.

FIG. 4 is a partial profile elevated perspective view showing variousaspects of the example portable trailer stabilizer of FIG. 3 accordingto at least some aspects of the present disclosure.

FIG. 5 is a partial front elevated perspective view showing variousaspects of the example portable trailer stabilizer of FIG. 3 accordingto at least some aspects of the present disclosure.

FIG. 6 is a narrowed partial profile elevated perspective view showingvarious aspects of the example portable trailer stabilizer of FIG. 3according to at least some aspects of the present disclosure.

FIG. 7 is a narrowed partial rear profile elevated perspective viewshowing various aspects of the example portable trailer stabilizer ofFIG. 3 according to at least some aspects of the present disclosure.

FIG. 8 is a front perspective view of a further example portable trailerstabilizer, depicted with signaling in the notification positionaccording to at least some aspects of the present disclosure.

FIG. 9 is a rear perspective view of the portable trailer stabilizer ofFIG. 8 with signaling in the notification position.

FIG. 10 is a front perspective view of the portable trailer stabilizerof FIG. 8 with signaling in the transport position.

FIG. 11 is a rear elevation view of the portable trailer stabilizer ofFIG. 8 with signaling in the transport position.

FIG. 12 is a perspective view of another example portable trailerstabilizer showing various aspects of an example portable trailerstabilizer according to at least some aspects of the present disclosure.

FIG. 12A is a plan view of the portable trailer stabilizer of FIG. 12shown with a wheeled configuration.

FIG. 13 is a plan view of the portable trailer stabilizer of FIG. 12.

FIG. 14 is a side elevation view of the portable trailer stabilizer ofFIG. 12.

FIG. 15 is a rear elevation view of the portable trailer stabilizer ofFIG. 12.

FIG. 16 is a simplified side elevation view of a first example terminaltractor including a trailer stabilizer positioning element separate fromthe terminal tractor's fifth wheel, all according to at least someaspects of the present disclosure.

FIG. 17 is a simplified side elevation view of a second example terminaltractor including a trailer stabilizer positioning element separate fromthe terminal tractor's fifth wheel, all according to at least someaspects of the present disclosure.

FIG. 18 is a front elevation view of a third example terminal tractorincluding a trailer stabilizer positioning element separate from theterminal tractor's fifth wheel, all according to at least some aspectsof the present disclosure.

FIG. 19 is a simplified side elevation view of yet another exemplaryterminal tractor including a trailer stabilizer positioning elementseparate from the terminal tractor's fifth wheel, all according to atleast some aspects of the present disclosure.

FIG. 20 is a front elevation view of the exemplary terminal tractor ofFIG. 19.

FIG. 21 is a perspective view of an example indicator according to atleast some aspects of the present disclosure.

FIG. 22 is an exemplary diagram for a closed hydraulic system inaccordance with the instant disclosure.

FIG. 23 is a further exemplary diagram for a closed hydraulic system inaccordance with the instant disclosure.

FIG. 24 is still a further exemplary diagram for a closed hydraulicsystem in accordance with the instant disclosure.

DETAILED DESCRIPTION

Example embodiments according to the present disclosure are describedand illustrated below to encompass devices, methods, and techniquesrelating to supports utilized to stabilize and/or support parkedtrailers, such as portable stabilizers and/or stabilizing systems thatmay be used, for example, with semi-trailers parked at loading dockswhile loading and/or unloading contents. Of course, it will be apparentto those of ordinary skill in the art that the embodiments discussedbelow are examples and may be reconfigured without departing from thescope and spirit of the present disclosure. It is also to be understoodthat variations of the example embodiments contemplated by one ofordinary skill in the art shall concurrently comprise part of theinstant disclosure. However, for clarity and precision, the exampleembodiments as discussed below may include optional steps, methods, andfeatures that one of ordinary skill should recognize as not being arequisite to fall within the scope of the present disclosure. Variousexample embodiments are described and, unless specifically excluded, anyelement, feature, aspect, or operation described in connection with anyexample embodiment may be utilized in any combination in connection withany other embodiment. Moreover, in the example embodiments describedherein, unless specifically noted as being necessary or indispensable,any element, feature, aspect, or operation described in connection withany example embodiment or in any combination may be omitted inconnection with that embodiment or any other embodiment or combinationof embodiments.

FIG. 1 depicts an example portable trailer stabilizer system 10 that mayinclude and/or may be used in connection with one or more semi-trailers100, which may be parked on a support surface 102, such as in a parkinglocation proximate a building 104. For example, the building 104 mayinclude a loading dock having one or more loading dock bays 104A, witheach bay having a loading dock opening that may be selectively openedand closed by an overhead door. The trailer 100 may be transportedrelatively long distances by an over-the-road tractor 106 and/or thetrailer may be transported relatively short distances by a terminaltractor 108, 110. When the trailer 100 is parked, a portable trailerstabilizer 200, 300 may be positioned proximate the trailer 100 andready to stabilize and/or support at least a portion of the trailer 100.For example, the terminal tractor 108, 110 may be used to position theportable trailer stabilizer 200, 300 proximate a forward end portion 118of the trailer 100, such as beneath the forward end portion 118 of thetrailer 100 and between the trailer 100 and the support surface 102.Generally, as used herein, “tractor” may refer to a vehicle that isconfigured to pull, push, carry, and/or reposition another piece ofequipment and includes over-the-road tractors 106, terminal tractors108, 110, lift trucks, and/or other vehicles suitable for performingsimilar functions. For brevity, the following description focuses ontractors 106, 108, 110; however, it will be understood that othertractors may be utilized in similar manners in accordance with theinstant disclosure.

In some example embodiments, a tractor such as the terminal tractor 108,110 may be used to reposition the portable trailer stabilizer 200, 300proximate the trailer 100. Some example portable trailer stabilizers 200may be configured to be repositioned by towing (e.g., pulling and/orpushing) by a terminal tractor 108, 110 using the terminal tractor'sfifth wheel 112, 114, which it may also use for repositioning trailers100. Some example portable trailer stabilizers 300 may be configured tobe repositioned by lifting and carrying by a terminal tractor 110 usinga trailer stabilizer positioning element 116 separate from the terminaltractor's fifth wheel 114.

Turning to FIG. 2, the portable trailer stabilizer 200 may be configuredto extend between the support surface 102 (e.g., ground) and theunderside of the forward end portion 118 of the trailer 100, such as tostabilize and/or support the forward end portion 118 of the trailer 100.Alternatively, as discussed hereafter, the trailer stabilizer 200 may bepositioned not to contact the trailer 100 unless the landing gear of thetrailer fails or significantly sags, or the trailer frame bends underload. While FIG. 2 depicts the portable trailer stabilizer 200 asconcurrently contacting the support surface 102 and the underside of theforward end portion 118, it is within the scope of the disclosure forthere to be a gap between the portable trailer stabilizer 200 and atleast one of the support surface 102 and the underside of the forwardend portion 118 of the trailer 100.

The portable trailer stabilizer 200 may include a support surfaceengagement element, such as a ground pad 202, which may be configured toselectively engage the support surface 102. The portable trailerstabilizer 200 may include a trailer engagement element, such as atrailer engagement bar 204, which may be configured to selectivelyengage the trailer 100. The trailer engagement bar 204 may be arrangedto extend generally horizontally and/or generally laterally (e.g.,side-to-side) beneath the forward end portion 118 of the trailer 100. Insome example embodiments, the trailer engagement bar 204 may beconstructed from a section of metal channel or tube, such as round tube.

In some example embodiments, the support surface engagement element 202and the trailer engagement element 204 may be operatively connected byone or more structural elements 206, 208 and/or one or more actuators,such as one or more hydraulic cylinders 210. In other exampleembodiments, alternative actuators may be used, such as pneumatic orelectrical actuators, electromechanical jacks, and/or a spring liftingapparatus with a ratchet and pawl mechanism to vertically reposition thetrailer engagement element 204 with respect to the support surfaceengagement element 202. The actuators 210 may be configured tofacilitate vertical repositioning, such as extension and/or retraction,of the trailer engagement element 204 relative to the support surfaceengagement element 202. For example, when pressurized hydraulic fluid isdirected to the hydraulic cylinder 210, the hydraulic cylinder 210 mayextend to extend the trailer engagement element 204 relative to thesupport surface engagement element 202. As used herein, “pressurized”may refer to a pressure greater than ambient atmospheric pressure.

In some example embodiments, the trailer engagement element (e.g.,trailer engagement bar 204) may be coupled to the structural elements206, 208 and/or the actuators (e.g., hydraulic cylinders 210) by one ormore pivot connections 210A (see FIG. 4). For example, some pivotconnections may allow the trailer engagement bar 204 to tiltside-to-side with respect to the trailer. Accordingly, the portabletrailer stabilizer 200 may accommodate uneven support surfaces 102,support surfaces 102 having debris thereon, and/or tilted semi-trailers100, for example.

In some example embodiments, the actuator 210 may be powered by anon-board, self-contained energy source. For example, the hydrauliccylinder 210 may be operatively connected to an on-board, self-containedhydraulic system 212. As used herein, “on-board” may refer to acomponent or clarity, as used herein, an energy source may be“self-contained” even if it stores energy resulting from externallyapplied forces, provided that the application of the externally appliedforces is incidental to operation of the portable trailer stabilizer.

In some example embodiments, the hydraulic system 212 may include one ormore hydraulic accumulators 214, one or more isolation valves 216 (e.g.,ball valves), one or more relief valves 217, and/or one or morehydraulic conduits 218 in selective fluid communication with theaccumulator 214 and the cylinder(s) 210. The hydraulic system 212 maycomprise a closed hydraulic system. As used herein, “closed hydraulicsystem” may refer to operatively connected hydraulic components that areconfigured for normal operation without supplying hydraulic fluid toand/or receiving hydraulic fluid from an external component. Forexample, the hydraulic system 212 may be configured so that hydraulicfluid flows between the accumulator 214 and the cylinder(s) 210 via theconduits 218 and valves 216, 217 without external connections (duringnormal use). As used herein, “closed hydraulic system” may include ahydraulic system that occasionally receives supplemental hydraulicfluid, such as to replace hydraulic fluid lost due to leakage.

In some alternative example embodiments, a hydraulic system may utilizean external pump (e.g., located on board the stabilizer 200, 300 and/oron a tractor), such as to raise and/or lower the trailer engagementelement 204. Some example on board pumps may utilize a battery with asolar charger and/or may be configured for charging from an externalcharger or dedicated power supply such as a corded outlet. In someexample embodiments, limit and/or pressure switches may limit the travelof the trailer engagement element 204.

In some example embodiments, the hydraulic fluid throughout the closedhydraulic system may be pressurized, such as at all times during normaloperation. For example, some example closed hydraulic systems may notinclude a vented reservoir (e.g., at about atmospheric pressure).Although FIG. 2 schematically illustrates one hydraulic cylinder 210coupled to one accumulator 214 via one isolation valve 216 for clarity,some example embodiments may include one or more (e.g., two) hydrauliccylinders 210, one or more accumulators 214, one or more relief valves217, and/or one or more (e.g., two) isolation valves 216 (or other flowcontrol devices) interconnected by any number of conduit 218 segments.

In some example embodiments, the isolation valve 216 may be operated(e.g., opened and/or shut) by an isolation valve operator mechanism,such as a valve operator element 220 and/or a cable 222 operativelyconnecting the valve operator element 220 to the isolation valve 216. Inother example embodiments, isolation valve operator mechanisms mayinclude mechanical linkages, electrical actuators, and/or hydraulicactuators arranged to open and/or shut the isolation valve 216.

In some example embodiments, the isolation valve operator mechanism(e.g., valve operator element 220) may be configured for operation inconnection with coupling the portable trailer stabilizer 200 to atractor 106, 108 and/or uncoupling the portable trailer stabilizer 200from a tractor 106, 108. For example, the isolation valve operatormechanism may be configured so that it is actuated by the act ofcoupling the portable trailer stabilizer 200 to a tractor 106, 108and/or the act of uncoupling the portable trailer stabilizer 200 from atractor 106, 108 (e.g., without additional action by an operator). Forexample, the valve operator element 220 may comprise a valve operatorplate coupled to a positioning element engagement element, such as afifth wheel plate 224, via a pivot 226. In operation, the valve operatorelement 220 may be configured so that when a terminal tractor's trailerstabilizer positioning element, such as a fifth wheel 112, 114, engagesor disengages the fifth wheel plate 224 of the portable trailerstabilizer 200, the valve operator element 220 is pivoted.Repositioning, such as by pivoting, the valve operator element 220 mayoperate (e.g., open and/or shut) the isolation valve 216 via the cable222. For example, the isolation valve operator mechanism may beconfigured so that when the fifth wheel plate 224 of the portabletrailer stabilizer 200 is disengaged from the terminal tractor's fifthwheel 112, 114, the isolation valve 216 may be shut and/or when thefifth wheel plate 224 of the portable trailer stabilizer 200 is engagedwith the terminal tractor's fifth wheel 112, 114, the isolation valve216 may be open. Some example embodiments may include one or more wheels228 configured to support the portable trailer stabilizer 200 on thesupport surface 102 during repositioning. The wheels 228 may facilitaterepositioning of the portable trailer stabilizer 200 by towing (e.g.,pulling and/or pushing), such as when the portable trailer stabilizer'sfifth wheel plate 224 is coupled to the terminal tractor's fifth wheel112, 114.

Referring to FIGS. 3 and 4, in some example embodiments, the trailerengagement element 204 may be pivotably disposed with respect to one ormore of the structural elements 206, 208. For example, the trailerengagement bar 204 may be coupled to the structural element 206 by apivot 206A that may include a pivot pin, which may allow the trailerengagement bar 204 to move generally upward and downward (e.g., at aradius from the pivot 206A) while extending and/or compressing thehydraulic cylinder 210.

In some example embodiments, the trailer engagement element (e.g.,trailer engagement bar 204) may comprise a sloped engagement surface204A. The engagement surface 204A may be arranged to contact the forwardend portion 118 of the trailer 100 when the portable trailer stabilizer200 is positioned beneath the forward end portion 118. When the trailerengagement bar 204 is higher than the underside of the forward endportion 118 of the trailer 100, the engagement surface 204A may contactand slide beneath and along the forward end portion 118 underside as theportable trailer stabilizer 200 is moved underneath the forward endportion 118. Accordingly, contact between a forward edge and theunderside of the trailer 100 and the engagement surface 204A and/or thetrailer engagement bar 204 may press the trailer engagement bar 204downward, thus compressing the hydraulic cylinder 210.

FIG. 8 is a front perspective view of a further example portable trailerstabilizer 1200, depicted with signaling in the notification position.FIG. 9 is a rear perspective view of the portable trailer stabilizer1200 with signaling in the notification position, FIG. 10 is a frontperspective view of the portable trailer stabilizer 1200 with signalingin the transport position, and FIG. 11 is a rear elevation view of theportable trailer stabilizer 1200 with signaling in the transportposition, all according to at least some aspects of the presentdisclosure. Generally, portable trailer stabilizer 1200 may be similarin construction and operation to portable trailer stabilizer 200described above. Repeated description of some similar features andoperations is omitted for brevity.

Referring to FIGS. 8-11, generally, the portable trailer stabilizer 1200may be configured to extend between the support surface 102 and theunderside of the forward end portion 118 of the trailer 100 (FIG. 1),such as to stabilize and/or support the forward end portion 118 of thetrailer 100.

The portable trailer stabilizer 1200 may include a support surfaceengagement element, such as a ground pad 1202, which may be configuredto selectively engage the support surface 102. The portable trailerstabilizer 1200 may include a trailer engagement element, such as atrailer engagement bar 1204, which may be configured to selectivelyengage the trailer 100 (FIG. 1). The trailer engagement bar 1204 may bearranged to extend generally horizontally and/or generally laterally(e.g., side-to-side) beneath the forward end portion 118 of the trailer100. In some example embodiments, the trailer engagement bar 1204 may beconstructed from a section of metal channel or tube, such as round tube.

In some example embodiments, the support surface engagement element 1202and the trailer engagement element 1204 may be operatively connected byone or more structural elements 1206, 1208 and/or one or more actuators,such as one or more hydraulic cylinders 1210. In other exampleembodiments, alternative actuators may be used, such as pneumatic orelectrical actuators, electromechanical jacks, and/or a spring liftingapparatus with a ratchet and pawl mechanism to lift the trailerengagement element and secure it in place. The actuators may beconfigured to facilitate extension and/or retraction of the trailerengagement element relative to the support surface engagement element.For example, when pressurized hydraulic fluid is directed to thehydraulic cylinder 1210, the hydraulic cylinder 1210 may extend toextend/raise the trailer engagement element 1204 relative to the supportsurface engagement element 1202.

In some example embodiments, the trailer engagement element (e.g.,trailer engagement bar 1204) may be coupled to the structural elements1206, 1208 and/or the actuators (e.g., hydraulic cylinders 1210) by oneor more pivot connections 1210A. For example, some pivot connections mayallow the trailer engagement bar 1204 to tilt side-to-side with respectto the trailer 100. Accordingly, the portable trailer stabilizer 1200may accommodate uneven support surfaces 102, support surfaces 102 havingdebris thereon, and/or tilted semi-trailers 100, for example.

In some example embodiments, the actuator may be powered by an on-board,self-contained energy source. For example, the hydraulic cylinders 1210may be operatively connected to an on-board, self-contained hydraulicsystem 1212. In some example embodiments, the hydraulic system 1212 mayinclude one or more hydraulic accumulators 1214, one or more isolationvalves 1216 (e.g., ball valves), and/or one or more hydraulic conduits1218 fluidically connecting the accumulator 1214 to the cylinders 1210via the isolation valves 1216. The hydraulic system 1212 may comprise aclosed hydraulic system. The hydraulic system 1212 may be configured sothat hydraulic fluid flows between the accumulator 1214 and thecylinders 1210 via the conduits 1218 and isolation valves 1216 withoutexternal connections (during normal use).

In some example embodiments, the isolation valves 1216 may be operated(e.g., opened and/or shut) by an isolation valve operator mechanism,such as a valve operator element 1220 and/or one or more rods 1222operatively connecting the valve operator element 1220 to the isolationvalves 1216. In other example embodiments, isolation valve operatormechanisms may include cables, electrical actuators, and/or hydraulicactuators arranged to open and/or shut the isolation valves 1216.

In some example embodiments, the isolation valve operator mechanism(e.g., valve operator element 1220) may be configured for operation inconnection with coupling the portable trailer stabilizer 1200 to atractor 106, 108 (FIG. 1) and/or uncoupling the portable trailerstabilizer 1200 from a tractor 106, 108. For example, the isolationvalve operator mechanism may be configured so that it is actuated by theact of coupling the portable trailer stabilizer 1200 to a tractor 106,108 and/or the act of uncoupling the portable trailer stabilizer 1200from a tractor 106, 108 (e.g., without additional action by anoperator). For example, the valve operator element 1220 may comprise avalve operator plate coupled to a positioning element engagementelement, such a fifth wheel plate 1224, via a pivot 1226. In operation,the valve operator element 1220 may be configured so that when aterminal tractor's trailer stabilizer positioning element, such as fifthwheel 112, 114, engages or disengages the fifth wheel plate 1224 of theportable trailer stabilizer 1200, the valve operator element 1220 ispivoted. Pivoting the valve operator element 1220 may operate (e.g.,open and/or shut) the isolation valve 1216 via the rod 1222. Forexample, the isolation valve operator mechanism may be configured sothat when the fifth wheel plate 1224 of the portable trailer stabilizer1200 is disengaged from the terminal tractor's fifth wheel 112, 114, theisolation valves 1216 may be shut and/or when the fifth wheel plate 1224of the portable trailer stabilizer 1200 is engaged with the terminaltractor's fifth wheel 112, 114, the isolation valves 1216 may be open.Some example embodiments may include one or more wheels 1228, which mayfacilitate repositioning the portable trailer stabilizer 1200, such aswhen the portable trailer stabilizer's fifth wheel plate 1224 is coupledto the terminal tractor's fifth wheel 112, 114.

In some example embodiments, the trailer engagement element 1204 may bepivotably disposed with respect to one or more of the structuralelements 1206, 1208. For example, the trailer engagement bar 1204 may becoupled to the structural element 1206 by a pivot 1206A, which may allowthe trailer engagement bar 204 to move generally upward and downward(e.g., at a radius from the pivot 1206A) while extending and compressingthe hydraulic cylinder 1210.

In some example embodiments, the trailer engagement element (e.g.,trailer engagement bar 1204) may comprise a sloped engagement surface1240A. The engagement surface 1240A may be arranged to contact theforward end portion 118 of the trailer 100 (FIG. 1) when the portabletrailer stabilizer 1200 is positioned beneath the forward end portion118. When the trailer engagement bar 1204 is higher than the undersideof the forward end portion 118 of the trailer 100, the engagementsurface 1240A may contact a leading forward edge of the trailer and/or afront face of the trailer and thereafter slide along and underneath theforward end portion 118 as the portable trailer stabilizer 1200 is movedunderneath the forward end portion 118. Accordingly, the contact betweenthe trailer 100 and at least one of the engagement surface 1240A and thetrailer engagement bar 1204 may press the trailer engagement bar 1204downward, thus compressing the hydraulic cylinder 1210.

In some example embodiments, the trailer stabilizer 1200 may include oneor more signal elements 1250, 1252. For example, a flag rod 1250 maypivot between a generally horizontal travel position and a generallyvertical notification position to indicate whether the isolation valves1216 are open or shut. In the illustrated embodiment, the flag rod 1250is pivoted by a mechanical linkage (e.g., rod) operatively coupled tothe valve operator element 1220. When the isolation valves 1216 areshut, the flag rod 1250 is in the generally horizontal travel or stowedposition. When the isolation valves are open, the flag rod 1250 is inthe generally vertical notification position. Those skilled in the artwill understand that the horizontal and vertical positions of the flagrod 1250 may be switched so that a horizontal position reflects theisolation valves are open, whereas a vertical position reflects that theisolation valves are closed. Accordingly, an operator of a tractor 106,108 can readily determine whether the isolation valves 1216 are open orshut using the position of the flag rod 1250. In addition, when the flagrod 1250 is in the generally horizontal notification position, a dockattendant inside the loading dock may view or verify the position of theflag rod using a camera image of a video camera on the outside of theloading dock to provide a form of physical sight verification.

As another example, a full up indicator 1252 may pivot between a “fullup” position and a not “full up” position. In the illustratedembodiment, the full up indicator displays a flag to the operator of atractor 106, 108 (e.g., in a generally vertical position) when thetrailer engagement element 1204 is at or near its fully raised position.When the trailer engagement element 1204 is below its fully raisedposition, the flag of the full up indicator 1252 drops to a generallyhorizontal position. In the illustrated embodiment, the full upindicator 1252 is pivotably disposed on the trailer engagement element1204 and is operated by a connector (e.g., cable), which is coupled toanother portion of the trailer stabilizer 1200 that does not move withthe trailer engagement element 1204. Accordingly, the operator of thetractor 106, 108 can readily determine whether the trailer engagementelement 1204 is at or near its fully raised position.

Referring to FIGS. 12-16, a further example portable trailer stabilizer300 may be configured to extend between a support surface 102 and theunderside of the forward end portion 118 of the trailer 100, such as tostabilize and/or support the forward end portion 118 of the trailer 100.Alternatively, as discussed hereafter, the trailer stabilizer 300 may bepositioned to not contact the trailer 100 unless the landing gear of thetrailer fails or significantly sags, or the trailer frame bends underload. Portable trailer stabilizer 300 may be similar to portable trailerstabilizer 200, 1200 in construction and operation except that portabletrailer stabilizer 300 may be configured to be repositioned by liftingand carrying using a trailer stabilizer positioning element 116 separatefrom the fifth wheel 112, 114 of the tractor 108, 110 as shown in FIG. 1and described in more detail below. Repeated description of elements incommon may be omitted for brevity.

The portable trailer stabilizer 300 may include a support surfaceengagement element, such as a ground pad 302, which may be configured toselectively engage the support surface 102. The portable trailerstabilizer 300 may include a trailer engagement element, such as atrailer engagement bar 304 arranged to extend generally horizontallyand/or generally laterally (e.g., side-to-side) beneath the forward endportion 118 of the trailer 100. In some example embodiments, the trailerengagement bar 304 may be constructed from a section of metal channel ortube, such as round tube.

In some example embodiments, the support surface engagement element 302and the trailer engagement element 304 may be operatively connected byone or more structural elements 306, 308 and/or one or more actuators,such as one or more hydraulic cylinders 310. In other exampleembodiments, alternative actuators may be used, such as pneumatic orelectrical actuators and/or electromechanical jacks, and/or springs,and/or ratchets, and/or pawls. The actuators may be configured tofacilitate extension and/or retraction of the trailer engagement element304 relative to the support surface engagement element 302.

In some example embodiments, the trailer engagement element (e.g.,trailer engagement bar 304) may be coupled to the structural elements306, 308 and/or the actuators (e.g., hydraulic cylinders 310) by one ormore pivot connections 310A that may include a pivot pin. For example,some pivot connections may allow the trailer engagement bar 304 to tiltside-to-side with respect to the trailer, in addition to pivotingfront-to-rear. Accordingly, the portable trailer stabilizer 300 mayaccommodate debris and uneven support surfaces 102 and/or tiltedsemi-trailers 100, for example.

In some example embodiments, the actuators may be powered by one or moreon-board, self-contained energy sources. For example, the hydrauliccylinders 310 may be operatively connected to an on-board,self-contained hydraulic system 312. In some example embodiments, thehydraulic system 312 may include one or more hydraulic accumulators 314,one or more isolation valves 316 (e.g., ball valves), one or more reliefvalves 317, and/or one or more hydraulic conduits 318 fluidicallyconnecting the accumulator 314, the cylinders 310, and valves 316, 317.Although the example embodiment of FIGS. 12-15 is shown with twohydraulic cylinders 310 coupled to one accumulator 314 via respectiveisolation valves 316, some example embodiments may include one or morehydraulic cylinders 310, one or more accumulators 314, and/or one ormore isolation valves 316 (or other flow control devices). In someexample embodiments, the isolation valves 316 may be operated (e.g.,opened and/or shut) by an isolation valve operator mechanism, such asvalve operator elements 320 and/or cables 322 operatively connecting thevalve operator elements 320 to the isolation valves 316. In otherexample embodiments, isolation valve operator mechanisms may includemechanical linkages, electrical actuators, and/or hydraulic actuatorsarranged to open and/or shut the isolation valves 316.

In some example embodiments, the isolation valve operator mechanism(e.g., valve operator elements 320) may be configured for operation inconnection with coupling the portable trailer stabilizer 300 to atractor 108 and/or uncoupling the portable trailer stabilizer from atractor 108. For example, the isolation valve operator mechanism 320 maybe configured so that it is actuated by the act of coupling the portabletrailer stabilizer 300 to a tractor 108 and/or the act of uncoupling theportable trailer stabilizer from a tractor 108. For example, theportable trailer stabilizer 300 may include one or more positioningelement engagement elements, such as conduits 324, configured to receiverespective arms 120 of the trailer stabilizer positioning element 116(described below). The conduits 324 of the portable trailer stabilizer300 may be spaced apart a distance corresponding to a distance betweenthe arms 120 of the trailer stabilizer positioning element 116. In someexample embodiments, the conduits 324 may include respective bell mouths326 to facilitate engagement of the arms 120 with the conduits 324.

In some example embodiments, the valve operator elements 320 may beconfigured so that when the arms 120 of the trailer stabilizerpositioning element 116 engage or disengage the conduits 324 of theportable trailer stabilizer 300, the valve operator elements 320 aremoved (e.g., pivoted). Moving the valve operator elements 320 mayoperate (e.g., open and/or shut) the isolation valves 316 via the cables322. For example, the isolation valve operator mechanism may beconfigured so that when the conduits 324 of the portable trailerstabilizer 300 are disengaged from the arms 120 of the trailerstabilizer positioning element 116, the isolation valves 316 are shutand/or when the conduits 324 of the portable trailer stabilizer 300 areengaged with the arms 120 of the trailer stabilizer positioning element116, the isolation valves 316 are opened.

In some example embodiments, the trailer engagement element 304 may bepivotably disposed with respect to one or more of the structuralelements 306, 308. For example, the trailer engagement bar 304 may becoupled to the structural element 306 by a pivot 306A that may include apin, which may allow the trailer engagement bar 304 to move generallyupward and downward (e.g., at a radius from the pivot 306A) whileextending and compressing the hydraulic cylinder 310. In some exampleembodiments, the trailer engagement element (e.g., trailer engagementbar 304) may comprise one or more sloped engagement surfaces 304A. Theengagement surfaces 304A may be arranged to contact a forward edge ofthe forward end portion 118 of the trailer 100 when the portable trailerstabilizer 300 is positioned beneath the forward end portion 118. Whenthe trailer engagement bar 304 is higher than the underside of theforward end portion 118 of the trailer 100, the engagement surfaces 304Amay contact and be forced downward to slide below and along the forwardend portion 118 as the portable trailer stabilizer 300 is movedunderneath the forward end portion 118. Accordingly, the contact betweenthe engagement surfaces 304A and/or the trailer engagement bar 304 maypress the trailer engagement bar 304 downward, thus shortening thehydraulic cylinders 310.

As depicted in FIG. 12A, the exemplary portable trailer stabilizer 300may include extended rails 336 to which are mounted an axle 330.Opposing ends of the axle 330 are mounted to respective wheel and tirecombinations 340. By incorporating the axle 330 and the wheel and tirecombinations 340, the exemplary portable trailer stabilizer 300 may berepositioned without requiring the entire stabilizer 300 to be liftedoff the ground.

Looking to FIG. 16, the arms 120 of the trailer stabilizer positioningelement 116 may be pivotable, such as about a pivot 122, so that thearms 120 may be pivoted between a generally horizontal extendedconfiguration and a generally vertical retracted configuration. In theextended configuration, the arms 120 may be pivotable above and/or belowgenerally horizontal, such as to facilitate engagement of the arms 120with a portable trailer stabilizer 300 that may be positioned on an evensupport surface 102 or on a tilted and/or uneven support surface 102. Insome example embodiments, the arms 120 may be pivoted by one or moreactuators, such as a hydraulic cylinder 124.

In some example embodiments, the trailer stabilizer positioning element116 may be vertically repositionable relative to the terminal tractor,such as to vary the height of the arms 120 above the support surface102. In some example embodiments, the trailer stabilizer positioningelement 116 may include one or more actuators, such as a hydrauliccylinder 126, which may be arranged to raise and/or lower the arms 120.

In some example embodiments, the trailer stabilizer positioning element116 may be horizontally repositionable relative to the terminal tractor,such as to vary the horizontal length of the arms 120 above the supportsurface 102. In some example embodiments, the trailer stabilizerpositioning element 116 may include one or more actuators, such as ahydraulic cylinder 124, which may be arranged to extend and contract thearms 120 and change the longitudinal length thereof.

Some example arms 120 may include an engagement element, such as a hook128, which may be disposed proximate a distal end portion of the arm120. Some example engagement elements may be configured to selectivelyretain a portable trailer stabilizer 300 on the arms 120. In someexample embodiments, one or more of the engagement elements (e.g., hooks128, 1120, 2120) may be arranged to move the isolation valve operatormechanism (e.g., by contacting the valve operator elements 320, 2320,1320) of the portable trailer stabilizer 300.

Turning to FIGS. 17 and 18, an example terminal tractor 1110 may includea fifth wheel (which may be used to couple to semi-trailers), a trailerstabilizer positioning element 1116 (which may be used to couple toportable trailer stabilizers), and/or an operator cab 1130. In thecontext of a remote or autonomous tractor 1110, the operator cab 1130may be optional. In some example embodiments, the trailer stabilizerpositioning element 1116 may comprise one or more generally laterallyoriented hooks 1120, which may be arranged on a forward portion of theterminal tractor 1110. For example, each hook 1120 may be generallyelongated and/or may have a generally upwardly facing opening. In somealternative example embodiments, one or more trailer stabilizerpositioning elements (e.g., one or more hooks 1120) may be arranged tooperate on one or multiple sides of the tractor 1110 (e.g., for sidedeployment of the stabilizer) and/or from the rear of the tractor 1110(e.g., for rearward deployment of the stabilizer).

In some example embodiments, the trailer stabilizer positioning element1116 may be vertically repositionable relative to the terminal tractor1100, such as to vary the height of the hooks 1120 above the supportsurface 102. In some example embodiments, the trailer stabilizerpositioning element 1116 may include one or more actuators, such as ahydraulic cylinder 1126, which may be arranged to raise and/or lower thehooks 1120. It should be noted that in lieu of hooks 1120, the trailerstabilizer positioning element may comprise an elongated trough.

In some example embodiments, the trailer stabilizer positioning element1116 may be horizontally repositionable relative to the terminal tractor1100, such as to vary the horizontal position of the device with respectto the terminal tractor. In some example embodiments, the trailerstabilizer positioning element 1116 may include one or more actuators,such as a hydraulic cylinder, which may be arranged to extend andcontract the horizontal position of the hook(s) 1120.

The terminal tractor 1100 including the trailer stabilizer positioningelement 1116 may be used with a further exemplary portable trailerstabilizer 1300 (see FIG. 17). The portable trailer stabilizer 1300 maybe generally similar to the earlier portable trailer stabilizer 300, andrepeated description of elements in common may be omitted for brevity.The portable trailer stabilizer 1300 may include one or more positioningelement engagement elements, such as inverted hooks or an invertedtrough 1324, which may be configured to selectively engage thehooks/trough 1120 of the trailer stabilizer positioning element 1116. Insome example embodiments, the hooks/trough 1324 of the portable trailerstabilizer 1300 may be generally laterally oriented and/or may include agenerally downwardly facing opening. One or more valve operator elements1320, which may be movably disposed within an opening defined by thehooks/trough 1324, may be configured so that engagement of thehooks/trough 1120 of trailer stabilizer positioning element 1116 of theterminal tractor 1110 with the hooks/trough 1324 of the portable trailerstabilizer 1300 may operate isolation valves in the manner describedabove. For example, engaging the hooks/trough 1324 with the hooks/trough1120 may move the valve operator element 1320, which may operate theisolation valves via an isolation valve operator mechanism 1322.

Referencing FIGS. 19 and 20, another example exemplary terminal tractor2110 is depicted that includes a trailer stabilizer positioning element2116 separate from the terminal tractor's fifth wheel. In exemplaryform, the terminal tractor 2110 may include a fifth wheel (which may beused to couple to semi-trailers), the trailer stabilizer positioningelement 2116 (which may be used to couple to portable trailerstabilizers), and/or an operator cab 2130. In some example embodiments,the trailer stabilizer positioning element 2116 may comprise one or morehooks 2120 (or a trough), which may be arranged on a forward portion ofthe terminal tractor 2110. For example, the hooks 2120 may be laterallyspaced apart and/or may have generally upwardly facing openings. In somealternative example embodiments, one or more trailer stabilizerpositioning elements (e.g., one or more hooks 2120) may be arranged tooperate on one or multiple sides of the tractor 2110 (e.g., for side ondeployment of the stabilizer) and/or from the rear of the tractor 2110(e.g., for rearward deployment of the stabilizer).

In some example embodiments, the trailer stabilizer positioning element2116 may be vertically repositionable relative to the terminal tractor2110, such as to vary the height of the hooks 2120 above the supportsurface 102. In some example embodiments, the trailer stabilizerpositioning element 2116 may include one or more actuators, such as ahydraulic cylinder 2126, which may be arranged to raise and/or lower thehooks 2120.

In some example embodiments, the trailer stabilizer positioning element2116 may be horizontally repositionable relative to the terminal tractor2110, such as to vary the horizontal spacing of the hooks 2120 relativeto a side (e.g., front, rear, left, right) of the terminal tractor. Insome example embodiments, the trailer stabilizer positioning element2116 may include one or more actuators, such as a hydraulic cylinder,which may be arranged to extend and contract to vary the horizontalposition of the hooks 2120 with respect to a side of the tractor.

The terminal tractor 2100 including the trailer stabilizer positioningelement 2116 may be used with a further example exemplary portabletrailer stabilizer 2300. The portable trailer stabilizer 2300 may begenerally similar to portable trailer stabilizers 300, 1300, andrepeated description of elements in common may be omitted for brevity.The portable trailer stabilizer 2300 may include one or more positioningelement engagement elements, such as a bar 2324, which may be configuredto selectively engage the hooks 2120 of the trailer stabilizerpositioning element 2116. In some example embodiments, the bar 2324 ofthe portable trailer stabilizer 2300 may be generally laterally orientedand/or generally horizontal. One or more valve operator elements 2320,which may be movably disposed relative to the bar 2324, may beconfigured so that engagement of the trailer stabilizer positioningelement 2116 of the terminal tractor 2110 with the bar 2324 of theportable trailer stabilizer 2300 may operate isolation valves in themanner described above. For example, the trailer stabilizer positioningelement 2116 of the terminal tractor 2110 may include a tractor valveoperator element 2118, which may be configured to engage a stabilizervalve operator element 2320, such as a pivotable plate. The stabilizervalve operator element 2320 may operate the isolation valves via anisolation valve operator mechanism 2322.

Referring back to FIGS. 12A and 12-15, some example portable trailerstabilizers 300 according to at least some aspects of the presentdisclosure may be configured in consideration of trailers havingundersides with varied spacings from the ground or a support surface.For example, some portable trailer stabilizers 300 may be configured toaccommodate trailers 100 with an undersurface at a given height 450 (seeFIG. 14). Some portable trailer stabilizers 300 may have a minimumheight 452, which may be less than the given trailer height 450, tofacilitate positioning of the portable trailer stabilizer 300 beneath anunderside of the trailer 100. For example, the minimum height 452 may bethe height of the portable trailer stabilizer 300 when the trailerengagement tube 304 is fully retracted relative to the ground pad 302.Some portable trailer stabilizers 300 may have a maximum height 454,which may be greater than or equal to the highest height of theundersurface of a trailer. For example, the maximum height 454 may bethe height of the portable trailer stabilizer 300 when the trailerengagement tube 304 is fully spaced relative to the ground pad 302. Insome example embodiments, the maximum height 454 of the stabilizer 300may comprise the minimum height 452 plus a travel range 456. Forexample, the travel range 456 may be the height above the minimum height452 that the trailer engagement tube 304 may be configured to occupy byoperation of the hydraulic cylinder 310. Although these heightparameters have been described in connection with the embodiment shownin FIGS. 12A and 12-15, similar height parameters may be applicable toother example stabilizer embodiments according to at least some aspectsof the present disclosure, such as the portable trailer stabilizers 200,1200, 1300, 2300 as described herein.

In some example embodiments according to at least some aspects of thepresent disclosure, the minimum height 452 may be about 40 inches toabout 42 inches. In some circumstances, such a minimum structure heightmay provide support for the semi-trailer should the repositioningmechanism of the trailer stabilizer bar 304 (e.g., hydraulics) fail. Insome example embodiments, the maximum height 454 may be about 52 inches.In some example embodiments, the structure of the stabilizer may beheight adjustable to facilitate use with trailer heights 450 out of thenormal travel range 456. In some such embodiments, adjusting theheight-adjustable structure may allow the structure to be reconfiguredto have lower or higher minimum heights 452 and maximum heights 454.Generally, stabilizers according to at least some aspects of the presentdisclosure may be constructed to operate at any heights necessary tofacilitate use with trailers of a particular height or range of heights.

Referring to FIG. 21, an indicator 400 may be included as part of anyone of the foregoing portable trailer stabilizers 200, 300, 1200, 1300,2300. The indicator 400 may include a signal element, such as apivotably disposed flag 402, which may be arranged to visually indicatewhether a portable trailer stabilizer is positioned to support a parkedtrailer. For example, when a trailer engagement bar 404 (equivalent tothe stabilizer bars 204, 304, 1204) of a portable trailer stabilizer isnot engaged with the underside of a trailer, the flag 402 may be in thegenerally vertical, generally downward position shown in FIG. 21. Whenthe trailer engagement bar 404 of the portable trailer stabilizerapproximates or is in contact with the underside the trailer, the flag402 may extend generally horizontally and/or laterally outward from thestabilizer to evidence the stabilizer is in a support position withrespect to the parked trailer. For example, the indicator 400 mayinclude a linkage and roller 406 operatively coupled to the flag 402 sothat contact between the roller 406 and the undersurface of the parkedtrailer may result in repositioning of the flag 402. Accordingly, thestabilizer status of the portable trailer stabilizer may be determinedby individuals viewing the position of the indicator flag 402. In somecircumstances, the indicator flag 402 may be viewed directly byindividuals with a direct line of sight thereto, such as individuals inthe area of the portable trailer stabilizer. In some circumstances, theindicator flag 402 may be viewed indirectly by individuals utilizing aremote viewing device, such as individuals inside a warehouse viewingthe indicator flag 402 position on a screen displaying an image obtainedby a camera outside of the warehouse. In some example embodiments, theflag 402 may include reflective elements and/or other visibilityenhancing features to allow visual differentiation between the flag'sposition 402 reflecting the stabilizer in a stabilizing position versusa non-stabilizing position.

Some example methods of operating a portable trailer stabilizer aredescribed below. Various example methods according to at least someaspects of the present disclosure may include any combination of any oneor more of the steps or operations discussed below.

Some example methods of supporting or providing support for a trailerusing a portable trailer stabilizer 200, 1200, 300, 1300, 2300 mayinclude parking a trailer 100 in a desired location using a tractor 106,108, 110 and disconnecting the tractor 106, 108, 110 from the trailer100 (e.g., disconnecting the fifth wheel plate of the trailer from thefifth wheel of the tractor 106, 108, 110). For example, the tractor 106,108, 110 (e.g., while operatively coupled to the trailer 100) may bedriven rearward to reposition the trailer 100 at a loading dock bay104A. Upon termination of the repositioning, the trailer 100 may bedecoupled from the tractor 106, 108, 110, leaving the trailer 100 parkedin position. The tractor 106, 108, 110 (e.g., while operativelydecoupled from the trailer) may be driven forward to vacate the positionimmediately in front of the forward end portion 118 of the parkedtrailer 100.

A tractor 108, 110 may be coupled to a portable trailer stabilizer 200,1200, 300, 1300, 2300, which may be operative to open the isolationvalves 216, 1216, 316 of the portable trailer stabilizer. In particular,engagement of the stabilizer 200, 1200, 300, 1300, 2300 by the tractor108, 110 may be operative to reposition the isolation valves 216, 1216,316 so that fluid can flow between the actuators 210, 1210, 310 and theaccumulator 214, 1214, 314, as will be discussed in more detailhereafter. Repositioning the isolation valves 216, 1216, 316 may directhydraulic fluid to or from the hydraulic accumulator 214, 1214, 314 toor from the hydraulic cylinders 210, 1210, 310, thus varying theeffective length of the hydraulic cylinders 210, 1210, 310 (if notalready fully extended or fully retracted). By way of example, higherpressurized fluid from the hydraulic accumulator 214, 1214, 314 flowingto the hydraulic cylinders 210, 1210, 310 would be operative to extendthe hydraulic cylinders where the fluid pressure within the cylinders isless than that of the accumulator. Conversely, higher pressurized fluidfrom the hydraulic cylinders 210, 1210, 310 flowing to the accumulator214, 1214, 314 would be operative to retract the hydraulic cylinderswhere the fluid pressure within the cylinders is greater than that ofthe accumulator.

Coupling the tractor 108, 110 to the portable trailer stabilizer 200,1200, 300, 1300, 2300 may include coupling a trailer stabilizerpositioning element (e.g., fifth wheel 112, 114 and/or trailerstabilizer positioning element 116) of the tractor 108, 110 to apositioning element engagement element (e.g., fifth wheel plate 224and/or conduits 324) of the portable trailer stabilizer 200, 1200, 300,1300, 2300. In this fashion, the portable trailer stabilizer 200, 1200,300, 1300, 2300 may be repositioned by the tractor 108, 110 at leastpartially beneath and/or in contact with the underside of a forward endportion 118 of the parked trailer 100. For example, a tractor 108, 110(e.g., operatively coupled to the portable trailer stabilizer 200, 1200,300, 1300, 2300) may be driven forward to position the portable trailerstabilizer 200, 1200, 300, 1300, 2300 at least partially beneath theforward end portion 118 of the parked trailer 100. If the portabletrailer stabilizer 200, 1200 includes a fifth wheel plate 224, 1224 andthe tractor 108, 110 includes a fifth wheel 112, 114 disposed on a rearportion of the tractor 108, 110, positioning the portable trailerstabilizer 200, 1200 may include driving the tractor 108, 110 in arearward direction. If the portable trailer stabilizer 300 includes atleast one conduit 324 and the tractor 110 includes at least one extendedarm 120 disposed at a front end portion of the tractor 110, positioningthe portable trailer stabilizer 300 may include driving the tractor 110in a forward direction. If the portable trailer stabilizer 1300, 2300includes at least one hook or trough 1324, or bar 2324 and the tractor1110 includes at least one hook or trough 1324 disposed at a front endportion of the tractor 1110 or the tractor 2110 includes at least onehook 2120 disposed at a front end portion of the tractor 2110,positioning the portable trailer stabilizer 1300, 2300 may includedriving the tractor 110 in a forward direction.

A vertical surface of the forward end portion 118 of the trailer 100(and/or possibly the underneath surface of the trailer 100) may becontacted by the trailer engagement element (e.g., trailer engagementbar 204, 1204, 304 and/or sloped engagement surface 204A, 304A, 1240A)while the trailer engagement element is in a partial or fully extendedconfiguration. While at least a portion of the portable trailerstabilizer 200, 1200, 300, 1300, 2300 is being positioned beneath theforward end portion 118 of the trailer 100, the trailer engagementelement 204, 1204, 304 and/or sloped engagement surface 204A, 304A,1240A may be pressed against a bottom edge of the vertical surface ofthe forward end portion 118 of the trailer 100, which may move thetrailer engagement element from a partial or fully extendedconfiguration to a lesser extended configuration that may includecompressing the hydraulic cylinders 210, 1210, 310. Compressing thehydraulic cylinders 210, 1210, 310 may direct pressurized hydraulicfluid from the hydraulic cylinders 210, 1210, 310 to the hydraulicaccumulator 214, 1214, 314 via the open isolation valves 216, 1216, 316,where the pressurized hydraulic fluid may be stored in the accumulator214, 1214, 314.

While repositioning the stabilizer 200, 1200, 300, 1300, 2300 partiallyunderneath the trailer 100, the support surface engagement elements(e.g., ground pad 202, 1202, 302) may be repositioned to contact thesupport surface 102. Contact between the ground pads 202, 1202, 302 andthe support surface 102 may occur as the stabilizer is beingrepositioned horizontally or may occur after the horizontal position ofthe stabilizer is established. In either of the foregoing instances, atleast a portion of the stabilizer 200, 1200, 300, 1300, 2300 may bevertically repositioned toward the support surface 102 to establish orat least increase the contact between grounds pads 202, 1202, 302 andthe support surface. During this vertical repositioning (i.e., lowering)operation, the isolation valves 216, 1216, 316 may remain open, therebyallowing hydraulic fluid to flow between the accumulator 214, 1214, 314and the hydraulic cylinders 210, 1210, 310. Accordingly, the trailerengagement element 204, 1204, 304 may remain in contact with anunderside of the trailer 100 due to pressurized hydraulic fluid flowingfrom the accumulator 214, 1214, 314 to the hydraulic cylinders 210,1210, 310 and extending the hydraulic cylinders 210, 1210, 310.

In this manner, when the hydraulic system is closed, pressurized, andthe isolation valves 216, 1210, 316 are open, an equilibrium isestablished between the fluid within the hydraulic cylinders 210, 1210,310 and the fluid within the accumulator 214, 1214, 314 (as well as thefluid flowing throughout the system). Prior to reaching thisequilibrium, forces pushing down on the engagement element 204, 1204,304 and/or sloped engagement surface 204A, 304A, 1240A may be operativeto increase the hydraulic pressure within the hydraulic cylinders 210,1210, 310 and, if this increased pressure is greater than that of thehydraulic pressure within the accumulator 214, 1214, 314, fluid willflow from the hydraulic cylinders 210, 1210, 310 and toward theaccumulator 214, 1214, 314 until pressure within the systemequilibrates, presuming the isolation valves 216, 1210, 316 are open. Inthis manner, active loads on the engagement element 204, 1204, 304and/or sloped engagement surface 204A, 304A, 1240A may be operative toincrease the hydraulic pressure within the system after equilibration.Conversely, if forces pushing down on the engagement element 204, 1204,304 and/or sloped engagement surface 204A, 304A, 1240A are not operativeto increase or maintain the hydraulic pressure within the hydrauliccylinders 210, 1210, 310 to a pressure at or above that of hydraulicfluid within the accumulator 214, 1214, 314, then fluid will flow fromthe accumulator 214, 1214, 314 toward the hydraulic cylinders 210, 1210,310 (presuming the isolation valves 216, 1210, 316 are open), thuscausing the hydraulic cylinders to extend or increase in length. In thismanner, the absence of or lesser active loads on the engagement element204, 1204, 304 and/or sloped engagement surface 204A, 304A, 1240A may beoperative to decrease the hydraulic pressure within the system afterequilibration. And when the pressure within the system reachesequilibrium again, the hydraulic pressure of the cylinders 210, 1210,310 is approximately equal to the hydraulic pressure within theaccumulator 214, 1214, 314, which maintains the position of thecylinders 210, 1210, 310 (i.e., no contraction or extension) presumingthe isolation valves 216, 1210, 316 are open.

In exemplary application, when the hydraulic system is closed,pressurized, and the isolation valves 216, 1216, 316 are open, thehydraulic pressure of the system is operative to cause the hydrauliccylinders 210, 1210, 310 to extend to a maximum or near maximum length(unless otherwise governed). This maximum or near maximum length resultsin the trailer engagement element (e.g., trailer engagement bar 204,1204, 304) being positioned at a maximum height or near maximum height(unless otherwise governed). In this fashion, as the stabilizer 200,1200, 300, 1300, 2300 is positioned underneath the trailer 100, thetrailer engagement element (e.g., trailer engagement bar 204, 1204, 304and/or sloped engagement surface 204A, 304A, 1240A) may make contactwith a portion of the trailer (such as the lower leading edge, a forwardvertical surface, or a horizontal underneath surface) as the stabilizeris vertically and/or horizontally repositioned. In cases where thetrailer engagement element (e.g., trailer engagement bar 204, 1204, 304and/or sloped engagement surface 204A, 304A, 1240A) needs to have itsvertical positioned lowered to fit underneath the trailer 100, thestabilizer 200, 1200, 300, 1300, 2300 may be wedged with respect to thetrailer 100 so that the trailer exerts downward force on the trailerengagement element. Downward force on the trailer engagement element isresultantly transferred to the hydraulic cylinders 210, 1210, 310 andthe pressure of the fluid therein. In this manner, the downward force onthe trailer engagement bar 204, 1204, 304 and/or sloped engagementsurface 204A, 304A, 1240A (exerted by the trailer 100) is operative toincrease the hydraulic pressure and compress the hydraulic cylinders210, 1210, 310 to lower the trailer engagement element and allow it topass underneath the trailer, while the higher pressure fluid flows fromthe cylinders 210, 1210, 310 toward the accumulator 214, 1214, 314 asthe isolation valves 216, 1216, 316 are open. But because the hydraulicsystem is pressurized, the fluid reaches equilibrium and the upward anddownward forces acting on the trailer engagement element (e.g., trailerengagement bar 204, 1204, 304 and/or sloped engagement surface 204A,304A, 1240A) are equalized with respect to the hydraulic pressure of thefluid within the accumulator 214, 1214, 314 to maintain contact betweenthe underside of the trailer 100 and trailer engagement element. Uponreaching the final horizontal position of the stabilizer 200, 1200, 300,1300, 2300, underneath the trailer 100, at least a portion of thestabilizer may be repositioned (i.e., vertically lowered) so that thesupport surface engagement elements (e.g., ground pad 202, 1202, 302)thoroughly contact the support surface 102. In circumstances where atleast a portion of the stabilizer is vertically lowered so that thesupport surface engagement elements thoroughly contact the supportsurface, the trailer forces acting on the trailer engagement elementeffectively decrease during this vertical repositioning of thestabilizer 200, 1200, 300, 1300, 2300. As a result, the pressurizedhydraulic fluid within the system would be the dominant force, thuscausing the hydraulic cylinders 210, 1210, 310 to extend (i.e., increasein length) until reaching a maximum length or until the trailerengagement element contacts the undersurface of the trailer so that thedownward trailer forces are sufficient to oppose further extension ofthe hydraulic cylinders 210, 1210, 310.

After at least a portion of the stabilizer 200, 1200, 300, 1300, 2300 ispositioned appropriately (vertically, laterally, and horizontally)underneath a forward end 118 of the trailer 100, the tractor 108, 110may disengage from the portable trailer stabilizer 200, 1200, 300, 1300,2300. Disengagement between the tractor 108, 110 and the stabilizer 200,1200, 300, 1300, 2300 may coincide with shutting the isolation valve216, 1216, 316. More specifically, if the trailer stabilizer positioningelement includes a fifth wheel 112, 114 and the positioning elementengagement element includes a fifth wheel plate 224, 1224, disengagingthe tractor 108, 110 from the portable trailer stabilizer 200, 1200 mayinclude uncoupling the fifth wheel plate 224, 1224 of the portabletrailer stabilizer from the fifth wheel 112, 114 of the tractor 108,110. Disengaging the tractor 108, 110 from the portable trailerstabilizer 200, 1200 may include repositioning the valve operatorelement 220, 1220 to shut the isolation valve 216, 1216. If the trailerstabilizer positioning element includes an extended arm 120 and thepositioning element engagement element includes a conduit 324 configuredto receive the arm 120, disengaging the tractor 110 from the portabletrailer stabilizer 300 may include disengaging the conduit 324 of theportable trailer stabilizer 300 from the arm 120 of the tractor 110.Disengaging the tractor 110 from the portable trailer stabilizer 300,1300, 2300 may include moving the valve operator element 320, 1320, 2320to shut the isolation valves 316. Post disengagement, the tractor 108,110 (e.g., operatively decoupled from the portable trailer stabilizer200, 1200, 300, 1300, 2300) may be repositioned to vacate a positionimmediately in front of the forward end portion 118 of the parkedtrailer 100. In cases where the tractor 108, 110 disengages from aportable trailer stabilizer 200, 1200, the tractor may be driven forwardto finalize the tractor repositioning. Conversely, in cases where thetractor 108, 110 disengages from a portable trailer stabilizer 300,1300, 2300, the tractor may be driven backwards to finalize the tractorrepositioning.

As mentioned, when the stabilizer 200, 1200, 300, 1300, 2300 is in astabilized position having at least a portion of the stabilizerunderneath the forward end 118 of a parked trailer 100, the stabilizermay be operative to provide stabilization to the parked trailer duringloading and/or unloading of material/goods/contents to or from thetrailer. In one example, the stabilizer 200, 1200, 300, 1300, 2300 maybe actively in contact with an underside of the trailer 100. In anotherexample, the stabilizer 200, 1200, 300, 1300, 2300 may be spaced apartfrom the underside of the trailer 100. Both examples will be explainedhereafter.

In an instance where the stabilizer 200, 1200, 300, 1300, 2300 is in astabilization position that involves the stabilizer initially andthereafter being in contact with the underside of the trailer 100, thetrailer engagement element (e.g., trailer engagement bar 204, 1204, 304)will most generally be the portion of the stabilizer contacting thetrailer. For purposes of discussion, it may be presumed that the tractor108, 110 is disengaged from the portable trailer stabilizer 200, 1200,300, 1300, 2300 and that the isolation valve 216, 1216, 316 is closed,thereby discontinuing fluid communication between the hydrauliccylinders 210, 1210, 310 and the accumulator 214, 1214, 314. As aresult, the hydraulic fluid within the hydraulic cylinders 210, 1210,310 and conduits leading to the isolation valve 216, 1216, 316 is heldwithin a fixed volume and the hydraulic fluid generally embodies anincompressible fluid.

In a case where material/goods/contents are loaded onto the trailer 100,particularly at the forward end portion 118 of the trailer 100, and thetrailer engagement element contacts an underside of the trailer, thedownward force imparted by the trailer 100 upon the stabilizer 200,1200, 300, 1300, 2300 increases as more goods are loaded within thefront of the trailer. This increase in downward force is ultimatelyborne by the hydraulic cylinders 210, 1210, 310 and operates to increasethe pressure of the hydraulic fluid therein. But given that thehydraulic fluid is trapped, and is nearly incompressible, the increasedhydraulic pressure does not lead to appreciable retraction of thehydraulic cylinders 210, 1210, 310 given that the hydraulic fluid istrapped in a fixed volume. As a result, even if the landing gear of thetrailer 100 was to fail, the hydraulic cylinders 210, 1210, 310 areoperative to support the entire weight of the forward end portion 118 ofthe trailer 100, thus avoiding roll-over or tip-over of the trailer 100in an instance of landing gear partial or complete failure. A similarsequence applies to a trailer 100 unloaded with the stabilizer 200,1200, 300, 1300, 2300 in a stabilized position.

Where material/goods/contents are unloaded from the trailer 100,particularly from the forward end portion 118 of the trailer 100, andthe trailer engagement element contacts an underside of the trailer, thedownward forces imparted by the trailer 100 upon the stabilizer 200,1200, 300, 1300, 2300 decrease. This decrease in downward forces whenthe hydraulic cylinders 210, 1210, 310 are fully extended may lead to avertical gap being created between the underside of the trailer 100 andthe trailer engagement element (e.g., trailer engagement bar 204, 1204,304) as sag associated with the trailer frame at the forward end portion118 of the trailer is lessened. Conversely, a decrease in downwardforces when the hydraulic cylinders 210, 1210, 310 are not fullyextended may lead to no extension or a minimal extension of thehydraulic cylinders by lessening the downward forced applied to thestabilizer by the trailer while the hydraulic fluid continues to remainwithin a fixed volume as a result of the isolation valve 216, 1216, 316being closed and inhibiting fluid communication between the hydrauliccylinders 210, 1210, 310 and the accumulator 214, 1214, 314. In eitherinstance, however, the stabilizer 200, 1200, 300, 1300, 2300 maintainsitself in a stabilizing position so that if the landing gear of thetrailer 100 fails, the entire weight of the forward end portion of thetrailer is able to be held up by the stabilizer. Those skilled in theart are aware of the dynamic forces imparted upon trailers by forkliftsmoving therein, as well as pumping fluids within on-board tanks of asemi-trailer, which can cause landing gear failure even when a traileris being unloaded or is near empty. Consequently, stabilization oftrailers is important in both loading and unloading operations.

Conversely, in an instance where the stabilizer 200, 1200, 300, 1300,2300 is in a stabilization position that involves the stabilizerinitially being spaced apart from the underside of the trailer 100, thetrailer engagement element (e.g., trailer engagement bar 204, 1204, 304)will most generally be the portion of the stabilizer nearest to theunderside of the trailer. For purposes of discussion, it may be presumedthat the tractor 108, 110 is disengaged from the portable trailerstabilizer 200, 1200, 300 and that the isolation valve 216, 1216, 316 isclosed, thereby discontinuing fluid communication between the hydrauliccylinders 210, 1210, 310 and the accumulator 214, 1214, 314. As aresult, the hydraulic fluid within the hydraulic cylinders 210, 1210,310 and conduits leading to the isolation valve 216, 1216, 316 is heldwithin a fixed volume and the hydraulic fluid generally embodies anincompressible fluid.

In a case where material/goods/contents are loaded onto the trailer 100,particularly at the forward end portion 118 of the trailer 100, thedownward forces imparted by the trailer increase. This increase inforces on the trailer 100 may result in the trailer sagging, which mayor may not close the original spacing between the stabilizer 200, 1200,300, 1300, 2300 and the underside of the trailer, which may result incontact between the stabilizer and the underside of the trailer 100.Contact by the trailer 100 onto the stabilizer 200, 1200, 300, 1300,2300 results in some of the downward forces of the trailer beingultimately borne by the hydraulic cylinders 210, 1210, 310 and operatesto increase the pressure of the hydraulic fluid therein. But given thatthe hydraulic fluid is trapped, and is nearly incompressible, theincreased hydraulic pressure does not lead to appreciable retraction ofthe hydraulic cylinders 210, 1210, 310 given that the hydraulic fluid istrapped in a fixed volume. As a result, even if the landing gear of thetrailer 100 was to fail, the hydraulic cylinders 210, 1210, 310 areoperative to support the entire weight of the forward end portion 118 ofthe trailer 100, thus avoiding roll-over or tip-over of the trailer 100in an instance of landing gear failure. Conversely, if a gap ismaintained between the trailer 100 and the stabilizer 200, 1200, 300,1300, 2300, and forces acting on the trailer cause the landing gear tofail, the underside of the trailer will immediately contact the trailerengagement element (e.g., trailer engagement bar 204, 1204, 304) inorder to support the trailer. Given that the hydraulic fluid is trappedin a fixed volume, and is nearly incompressible, the increased hydraulicpressure that results on the hydraulic fluid trapped within thecylinders 210, 1210, 310 from the forward weight of the trailer beingborne by the stabilizer does not lead to appreciable retraction of thehydraulic cylinders 210, 1210, 310. As a result, even if the landinggear of the trailer 100 fails, the hydraulic cylinders 210, 1210, 310are operative to support the entire weight of the forward end portion118 of the trailer 100, thus avoiding roll-over or tip-over of thetrailer 100 in an instance of landing gear failure. A similar sequenceapplies to a trailer 100 unloaded with the stabilizer 200, 1200, 300,1300, 2300 in a stabilized position.

In a circumstance where the stabilizer 200, 1200, 300, 1300, 2300 ispositioned underneath the trailer 100 prior to the trailer beingunloaded, and a gap exists between the underside of the trailer and thestabilizer, this gap will generally be maintained or slightly increasedduring unloading of material/goods/contents from the trailer 100. By wayof example, particularly at the forward end portion 118 of the trailer100, the downward forces imparted upon the trailer 100 decease asmaterial is unloaded from the front of the trailer, which may result ina lesser sag associated with the trailer frame at the forward endportion 118 of the trailer. If this lessening of sag occurs, thespacing/gap between the stabilizer 200, 1200, 300, 1300, 2300 and thetrailer may increase. Nevertheless, the spacing between the stabilizer200, 1200, 300, 1300, 2300 and the trailer does not negate thestabilization provided if the landing gear of the trailer 100 failsduring unloading. In a case of landing gear failure, the forward endportion 118 of the trailer 100 would be repositioned downward and negateany gap between the trailer and stabilizer, thereby coming to rest uponthe trailer engagement element (e.g., trailer engagement bar 204, 1204,304). Given that the hydraulic fluid is trapped in a fixed volume, andis nearly incompressible, the increased hydraulic pressure that resultsfrom the stabilizer bearing at least a portion of the weight of thetrailer is trapped within the cylinders 210, 1210, 310 and does not leadto appreciable retraction of the hydraulic cylinders 210, 1210, 310. Asa result, even if the landing gear of the trailer 100 fails, thehydraulic cylinders 210, 1210, 310 are operative to support the entireweight of the forward end portion 118 of the trailer 100, thus avoidingroll-over or tip-over of the trailer 100 in an instance of landing gearpartial or complete failure.

Turning to FIG. 22, a closed hydraulic system in accordance with theinstant disclosure that may be used with any of the stabilizers 200,1200, 300, 1300, 2300 may include a pair of hydraulic cylinders 210,1210, 310 are in selective fluid communication with an accumulator 214,1214, 314 via hydraulic lines 218, 1218, 318 and a pair of isolationvalves 216, 1216, 316. As discussed herein, when the stabilizer 200,1200, 300, 1300, 2300 is being repositioned from or to a stabilizedposition, the isolation valves 216, 1216, 316 may be open to allow fluidcommunication between the hydraulic cylinders 210, 1210, 310 and theaccumulator 214, 1214, 314. But when the stabilizer is in a stabilizedposition, the isolation valves 216, 1216, 316 may be closed todiscontinue fluid communication between the hydraulic cylinders 210,1210, 310 and the accumulator 214, 1214, 314. Thus, when the stabilizeris in a stabilized position, the hydraulic fluid in the cylinders anddownstream from the isolation valve in fluid communication with thecylinders occupies a fixed volume. In this manner, the stabilizer canhold up the load of the front portion of a trailer using a locked columnor volume of fluid. Conversely, when the isolation valves 216, 1216, 316are open to allow fluid communication between the hydraulic cylinders210, 1210, 310 and the accumulator 214, 1214, 314, weight applied to thestabilizers 200, 1200, 300, 1300, 2300 results in increased pressure ofthe hydraulic fluid at the hydraulic cylinders 210, 1210, 310, whichcauses the cylinders to retract and fluid to flow from the cylinders,through the isolation valves, and into the accumulator 214, 1214, 314until reaching an equilibrium. It should be noted that the accumulator214, 1214, 314 comprises a variable volume chamber to accommodatedifferent amounts of hydraulic fluid, while the chamber is pressurizedto maintain at least a minimum pressure on the hydraulic fluid. Asdiscussed herein, this minimum pressure may be sufficient to cause thehydraulic cylinders 210, 1210, 310 to fully extend or at least partiallyextend, rather than being fully retracted at a minimum length.

Looking at FIG. 23, a further exemplary closed hydraulic system inaccordance with the instant disclosure that may be used with any of thestabilizers 200, 1200, 300, 1300, 2300 may include a pair of hydrauliccylinders 210, 1210, 310 in selective fluid communication with anaccumulator 214, 1214, 314 via hydraulic lines 218, 1218, 318, a pair ofisolation valves 216, 1216, 316, and a pair of relief valves 217, 1217,317. As discussed herein, when the stabilizer 200, 1200, 300, 1300, 2300is being repositioned from or to a stabilized position, the isolationvalves 216, 1216, 316 may be open to allow fluid communication betweenthe hydraulic cylinders 210, 1210, 310 and the accumulator 214, 1214,314. But when the stabilizer is in a stabilized position, the isolationvalves 216, 1216, 316 may be closed to discontinue fluid communicationbetween the hydraulic cylinders 210, 1210, 310 and the accumulator 214,1214, 314 along a first path. Likewise, when the stabilizer is in astabilized position, the relief valves 217, 1217, 317 may be closed todiscontinue fluid communication between the hydraulic cylinders 210,1210, 310 and the accumulator 214, 1214, 314 along a second path. Thus,when the stabilizer is in a stabilized position, the hydraulic fluid inthe cylinders and downstream from the isolation valve in fluidcommunication with the cylinders occupies a fixed volume. In thismanner, stabilizer can hold up the load of the front portion of atrailer using a locked column or volume of fluid until a pressureexerted by the hydraulic fluid reaches a predetermined pressure. Thispredetermined pressure may be the result of an abrupt landing gearfailure or abrupt forces occurring as a result of loading/unloading ofthe trailer, thereby amplifying the force exerted upon the stabilizer(resulting from the dynamic forces being greater than the staticforces), and causing an abrupt spike in the hydraulic fluid pressurewithin the cylinders. Upon reaching the predetermined relief pressure,which may result from the forward portion of the trailer 100 crashingdownward onto the trailer engagement element (e.g., trailer engagementbar 204, 1204, 304), the relief valves 217, 1217, 317 may automaticallyopen to bleed off hydraulic pressure from the cylinders and to theaccumulator 214, 1214, 314 via the second path. In such a case, thebleeding action of the hydraulic fluid from the cylinders 210, 1210, 310causes the cylinders to gradually retract until reaching a minimumlength or until the hydraulic fluid within the cylinders is below thepredetermined relief pressure—whichever occurs first. In eithercircumstance, the result may include the trailer stabilizer 200, 1200,300, 1300, 2300 continuing to function as a support or functioning anewas a support with the stabilizer being in contact with the trailer.Accordingly, the stabilizer 200, 1200, 300, 1300, 2300 operates todampen the descent of the forward portion of the trailer 100 in cases oflanding gear partial or total failure or dynamic forces tending to sagthe trailer from loading/unloading of materials. Conversely, when theisolation valves 216, 1216, 316 are open to allow fluid communicationbetween the hydraulic cylinders 210, 1210, 310 and the accumulator 214,1214, 314, such as when the stabilizer is being repositioned, hydraulicfluid pressure between the hydraulic cylinders 210, 1210, 310 and theaccumulator 214, 1214, 314 along the first path may be equalized andcorrespondingly vary the length of the cylinders depending upon forcedapplied to the cylinders to counteract the hydraulic fluid pressure.

With reference to FIG. 24, a still further exemplary closed hydraulicsystem in accordance with the instant disclosure that may be used withany of the stabilizers 200, 1200, 300, 1300, 2300 may include a pair ofhydraulic cylinders 210, 310 are in selective fluid communication alonga first path with an accumulator 214, 1214, 314 via hydraulic lines 218,1218, 318 and a pair of one-way valves 219, 1219, 319. These samehydraulic cylinders 210, 1210, 310 are in selective fluid communicationalong a second path with the accumulator 214, 1214, 314 via hydrauliclines 221, 1221, 321 and a second set of valves 223, 1223, 323. When thestabilizer 200, 1200, 300, 1300, 2300 is being repositioned from or to astabilized position, the one-way valves 219, 1219, 319 allow fluidcommunication between the hydraulic cylinders 210, 1210, 310 and theaccumulator 214, 1214, 314 such that higher pressure fluid in theaccumulator is able to flow to the cylinders via the hydraulic lines218, 1218, 318, but higher pressure fluid in the cylinders is precludedfrom flowing through the one-way valves via the hydraulic lines 218,1218, 318 to the accumulator. When the stabilizer is in a stabilizedposition, the one-way valves 219, 1219, 319 remain able to be openedwhen the hydraulic pressure within the accumulator 214, 1214, 314 ishigher than the hydraulic pressure within the cylinders 210, 1210, 310.Similarly, the set of valves 223, 1223, 323 are normally closed when thestabilizer 200, 1200, 300, 1300, 2300 is being repositioned from or to astabilized position, as well as when the stabilizer is in a stabilizedposition. When the release valves 223, 1223, 323 are closed, fluidcommunication between the cylinders 210, 1210, 310 and the accumulator214, 1214, 314 is precluded within the hydraulic lines 221, 1221, 321.

When the stabilizer 200, 1200, 300, 1300, 2300 is in a stabilizedposition, the hydraulic fluid in the cylinders 210, 1210, 310 anddownstream from the one-way valves 219, 1219, 319 occupies a fixedvolume. In this manner, stabilizer can hold up the load of the frontportion of a trailer using a locked column of fluid as the downwardforce exerted by the trailer on the stabilizer 200, 1200, 300, 1300,2300 increases, without appreciable compression of the overall height ofthe stabilizer, because the one-way valves 219, 1219, 319 inhibit higherpressure fluid from traveling to the accumulator 214, 1214, 314.Conversely, in cases where the downward force on the front of thetrailer is reduced, such as when material is unloaded from the trailer,sag associated with the trailer may decrease, thereby causing theunderneath surface of the trailer to rise. This increase in height ofthe underside of the trailer may create a gap between the stabilizer200, 1200, 300, 1300, 2300 and the underneath surface of the trailer.Unlike the prior exemplary diagrams, the instant configuration allowsthe stabilizer 200, 1200, 300, 1300, 2300 to automatically react toincreases in height of the underside of the trailer, post location in astabilization position. In particular, as the downward force applied tothe stabilizer 200, 1200, 300, 1300, 2300 by the trailer decreases or iseliminated (e.g., resulting from unloading of materials from thetrailer), the pressure of the hydraulic fluid within the cylindersdecreases, which means that the hydraulic fluid pressure on theaccumulator 214, 1214, 314 side of the one-way valves 219, 1219, 319 isgreater than the hydraulic fluid pressure on the cylinder side of theone-way valves 219, 1219, 319. This pressure differential allows theone-way valves 219, 1219, 319 to open and push additional hydraulicfluid into the cylinders 210, 1210, 310, which causes the cylinders toextend until reaching a maximum extension or until contacting theundersurface of the trailer and reaching an equilibrium between thedownward force of the trailer and the hydraulic fluid pressure. In thismanner, the stabilizer 200, 1200, 300, 1300, 2300 is able to activelyreact to decreases in downward pressure coming from the trailer toreduce or eliminate any gap between the stabilizer and the underside ofthe trailer.

Similarly, when the stabilizer 200, 1200, 300, 1300, 2300 is in astabilized position, the hydraulic fluid in the cylinders 210, 1210, 310and upstream from the release valves 223, 1223, 323 occupies a fixedvolume. In this manner, stabilizer can hold up the load of the frontportion of a trailer using a locked column of fluid as the downwardforce exerted by the trailer on the stabilizer 200, 1200, 300, 1300,2300 increases, without appreciable compression of the overall height ofthe stabilizer. In a circumstance where the release valves 223, 1223,323 are relief valves, the valves will maintain a fixed volume until thehydraulic pressure exceeds a predetermined threshold pressure, whichwhen reached allows the valves to open and release the higher pressurehydraulic fluid to the accumulator 214, 1214, 314. Moreover, the reliefvalves may have a manual override that allows the valves to open whenthe stabilizer is 200, 1200, 300, 1300, 2300 engaged by a tractor 108,110 for repositioning of the stabilizer. Alternatively, the releasevalves 223, 1223, 323 may comprise any type of valve that allowsselective communication between the cylinders 210, 1210, 310 and theaccumulator 214, 1214, 314, such as, without limitation, isolationvalves that are opened upon engaged by a tractor 108, 110 forrepositioning of the stabilizer. In this fashion, higher pressure fluidwithin the cylinders 210, 1210, 310 may be routed to the accumulator214, 1214, 314 via manual control over the valves 223, 1223, 323 orautomatic opening of the valves when the stabilizer is 200, 1200, 300,1300, 2300 engaged by a tractor 108, 110 for repositioning of thestabilizer.

Returning to FIGS. 1-20, when it is desired to discontinue use of theportable trailer stabilizer 200, 1200, 300 with the trailer 100 (e.g.,when the trailer 100 no longer requires stabilization), the portabletrailer stabilizer 200, 1200, 300 may be moved from at least partiallybeneath and/or in contact with the forward end portion 118 of thetrailer 100 to a different location. Some example methods of moving aportable trailer stabilizer 200, 1200, 300 may include coupling atractor 108, 110 to a portable trailer stabilizer 200, 1200, 300, whichmay be positioned at least partially beneath and/or in contact with aforward end portion 118 of a parked trailer 100. Coupling the tractor108, 110 to the portable trailer stabilizer 200, 1200, 300 may beoperative to open the isolation valves 216, 1216, 316, such as by movingthe valve operator element 220, 1220, 320. Coupling the tractor 108, 110to the portable trailer stabilizer 200, 1200, 300 may include coupling atrailer stabilizer positioning element (e.g., fifth wheel 112, 114and/or trailer stabilizer positioning element 116) of the tractor 108,110 to a positioning element engagement element (e.g., fifth wheel plate224, 1224 and/or conduits 324) of the portable trailer stabilizer 200,1200, 300.

If the trailer stabilizer positioning element includes a fifth wheel112, 114 and the positioning element engagement element includes a fifthwheel plate 224, 1224, coupling the tractor 108, 110 to the portabletrailer stabilizer 200, 1200 may include coupling the fifth wheel plate224, 1224 of the portable trailer stabilizer 200, 1200 to the fifthwheel 112, 114 of the tractor 108, 110. Coupling the tractor 108, 110 tothe portable trailer stabilizer 200, 1200 may include pivoting the valveoperator element 220, 1220 to open the isolation valves 216, 1216. Ifthe portable trailer stabilizer 200, 1200 includes a fifth wheel plate224, 1224 and the tractor 108, 110 includes a fifth wheel 112, 114disposed on a rear portion of the tractor 108, 110, coupling the tractor108, 110 to the portable trailer stabilizer 200, 1200 may includedriving the tractor 108, 110 in a rearward direction.

If the trailer stabilizer positioning element includes an extended arm120 and the positioning element engagement element includes a channel324 configured to receive the arm 120, coupling the tractor 110 to theportable trailer stabilizer 300 may include engaging the at least onechannel 324 of the portable trailer stabilizer 300 with the at least onearm 120 of the tractor 110. Coupling the tractor 110 to the portabletrailer stabilizer 300 may include moving the valve operator element 320to open the isolation valve 316. If the portable trailer stabilizer 300includes at least one channel 324 and the tractor 110 includes at leastone extended arm 120 disposed at a front end portion of the tractor 110,coupling the tractor 110 to the portable trailer stabilizer 300 mayinclude driving the tractor 110 in a forward direction.

In some example embodiments, the support surface engagement element(e.g., ground pad 202, 1202, 302) may be raised above the supportsurface 102, which may include pressing the trailer engagement element(e.g., trailer engagement bar 204, 1204, 304) against the forward endportion 118 of the trailer 100 and/or compressing the hydrauliccylinders 210, 1210, 310. Compressing the hydraulic cylinders 210, 1210,310 may direct pressurized hydraulic fluid to the hydraulic accumulator214, 1214, 314 via the open isolation valves 216, 1216, 316. Thepressurized hydraulic fluid may be stored in the accumulator 214, 1214,314. The portable trailer stabilizer 200, 1200, 300 may be moved awayfrom the trailer 100 using the tractor 108, 110.

In some example embodiments, as the portable trailer stabilizer 200,1200, 300 moves away from the forward end portion 118 of the trailer100, the trailer engagement element (e.g., trailer engagement bar 204,1204, 304) may move out from beneath the forward end portion 118 of thetrailer 100. When the trailer engagement element is no longer in contactwith the trailer 100, pressurized hydraulic fluid from the hydraulicaccumulator 214, 1214, 314 may flow through the open isolation valves216, 1216, 316 to the hydraulic cylinders 210, 310, which may extend thehydraulic cylinders 210, 1210, 310. Extending the hydraulic cylinders210, 1210, 310 may extend the trailer engagement element relative to thesupport surface engagement element, such as to the fully extendedconfiguration.

Tractors 1110, 2110 comprising upwardly facing hooks 1120 and hooks2120, and portable trailer stabilizers 1300, 2300 comprisingcorresponding downwardly facing channels 1324 and bars 2324,respectively, may be operated in generally the same manner as describedabove with reference to tractors 110 having extended arms 120 andportable trailer stabilizers 300 have corresponding conduits 324.Repeated description is omitted for brevity.

Generally, in some example portable trailer stabilizers comprisinghydraulically operated components, the hydraulic fluid may comprise anyfluid suitable for use as a medium for hydraulically transferring power.Some such fluids may be substantially incompressible under expectedoperating conditions. For example, the hydraulic fluid may include oneor more of water, propylene glycol, a petroleum-based oil, and/or asynthetic oil.

Some example portable trailer stabilizers according to at least someaspects of the present disclosure may include location reportingdevices. For example, a portable trailer stabilizer may be provided witha satellite navigation system (e.g., Global Positioning System (GPS))unit configured to transmit its location via a wireless network, such asa local area network, a cellular network, and/or a satellitecommunications network.

The present disclosure contemplates that some known trailer stabilizersmay require an operator, such as a terminal tractor driver, to manuallyoperate various components of a trailer stabilizer. For example, theindividual may operate jacks or other mechanisms associated with thetrailer stabilizer while outside of the terminal tractor and on theground adjacent to the trailer stabilizer. Some example embodimentsaccording to at least some aspects of the present disclosure may allow aterminal tractor driver to position or remove a portable trailerstabilizer while remaining on the terminal tractor. Accordingly, in somecircumstances, some portable trailer stabilizers according to at leastsome aspects of the present disclosure may improve safety and/orefficiency of freight terminal operations involving parkedsemi-trailers.

Some example embodiments according to at least some aspects of thepresent disclosure may include trailer restraint and/or retentionfeatures, which may be configured to prevent movement of a parkedsemi-trailer. For example, restraint and/or retention features may beconfigured to couple to the king pin of a semi-trailer and/or to coupleto a ground cleat (e.g., anchor) secured on the support surface. Someexample restraint and/or retention features which may be used inconnection with various embodiments according to the present disclosureare disclosed in U.S. Pat. No. 9,656,637 and U.S. Patent ApplicationPublication No. 2021/0048141, each of which is incorporated by referencein its entirety.

Example methods of manufacturing apparatus according to at least someaspects of the present disclosure and components thereof may includeoperations associated with acquiring, producing, and assembling variousparts, elements, components, and systems described herein.

Unless specifically indicated, it will be understood that thedescription of any structure, function, and/or methodology with respectto any illustrative embodiment herein may apply to any otherillustrative embodiments. More generally, it is within the scope of thepresent disclosure to utilize any one or more features of any one ormore example embodiments described herein in connection with any otherone or more features of any other one or more other example embodimentsdescribed herein. Accordingly, any combination of any of the features orembodiments described herein is within the scope of this disclosure.

Following from the above description and invention summaries, it shouldbe apparent to those of ordinary skill in the art that, while themethods and apparatuses herein described constitute example embodimentsaccording to the present disclosure, it is to be understood that thescope of the disclosure contained herein is not limited to the aboveprecise embodiments and that changes may be made without departing fromthe scope of the disclosure. Likewise, it is to be understood that it isnot necessary to meet any or all of the identified advantages or objectsdisclosed herein in order to fall within the scope of the disclosure,since inherent and/or unforeseen advantages may exist even though theymay not have been explicitly discussed herein.

What is claimed is:
 1. A portable trailer stabilizer, comprising: asupport surface engagement element configured to selectively engage asupport surface; a trailer engagement element configured to selectivelyengage a forward end portion of a trailer; a hydraulic cylinderoperatively connected between the support surface engagement element andthe trailer engagement element, the hydraulic cylinder configured toextend the trailer engagement element relative to the support surfaceengagement element; an on-board, self-contained energy source comprisinga hydraulic accumulator operatively coupled to the hydraulic cylinder;an isolation valve fluidically interposing the hydraulic cylinder andthe hydraulic accumulator; a positioning element engagement elementconfigured to selectively couple with a trailer stabilizer positioningelement of a tractor; and a valve operator mechanism configured to (i)open the isolation valve when the when the positioning elementengagement element is coupled to the trailer stabilizer positioningelement of the tractor, and (ii) shut the isolation valve when thepositioning element engagement element is uncoupled from the trailerstabilizer positioning element of the tractor; wherein the hydrauliccylinder, the hydraulic accumulator, and the isolation valve areoperatively connected in a closed hydraulic system containing ahydraulic fluid.
 2. The portable trailer stabilizer of claim 1, whereinthe valve operator mechanism comprises a valve operator element movablydisposed relative to the positioning element engagement element andoperatively coupled to the isolation valve so that (i) the valveoperator element opens the isolation valve when the positioning elementengagement element is engaged with the trailer stabilizer positioningelement of the tractor, and (ii) the valve operator element shuts theisolation valve when the positioning element engagement element isdisengaged from the trailer stabilizer positioning element
 3. Theportable trailer stabilizer of claim 2, wherein the portable trailerstabilizer is configured for repositioning by towing by the tractor. 4.The portable trailer stabilizer of claim 3, wherein the trailerstabilizer positioning element of the tractor comprises a fifth wheel;wherein the positioning element engagement element comprises a fifthwheel plate configured to selectively couple with the fifth wheel; andwherein the valve operator element is movably disposed relative to thefifth wheel plate so that valve operator element moves when the fifthwheel plate is engaged with the fifth wheel and when the fifth wheelplate is disengaged from the fifth wheel.
 5. The portable trailerstabilizer of claim 2, wherein the portable trailer stabilizer isconfigured for repositioning by lifting and carrying by the tractor. 6.The portable trailer stabilizer of claim 5, wherein at least one of (i)the positioning element engagement element comprises a channelconfigured to receive the portable trailer stabilizer positioningelement, the portable trailer stabilizer positioning element comprisingan extended arm; (ii) the positioning element engagement elementcomprises a downwardly facing channel configured to receive the portabletrailer stabilizer positioning element, the portable trailer stabilizerpositioning element comprising an upwardly facing channel; and (iii) thepositioning element engagement element comprises a bar configured toreceive the portable trailer stabilizer positioning element, theportable trailer stabilizer positioning element comprising a hook. 7.The portable trailer stabilizer of claim 1, wherein the hydrauliccylinder is configured to at least partially support the forward endportion of the trailer when the support surface engagement element isengaged with the support surface, the trailer engagement element isengaged with the forward end portion of the trailer, and the isolationvalve is shut.
 8. The portable trailer stabilizer of claim 1, whereinthe hydraulic fluid is pressurized throughout the closed hydraulicsystem.
 9. The portable trailer stabilizer of claim 1, wherein thetrailer engagement element comprises a trailer engagement bar arrangedto be positioned generally horizontally and generally laterally beneaththe forward end portion of a trailer.
 10. The portable trailerstabilizer of claim 1, wherein the trailer engagement element comprisesa sloped engagement surface arranged to contact the forward end portionof the trailer while the portable trailer stabilizer is being positionedbeneath the forward end portion of the trailer.
 11. The portable trailerstabilizer of claim 10, wherein the sloped engagement surface isconfigured to contact and slide along the forward end portion of thetrailer as the portable trailer stabilizer is moved underneath theforward end portion of the trailer.
 12. A portable trailer stabilizer,comprising: a support surface engagement element configured toselectively engage a support surface; a trailer engagement elementconfigured to selectively engage a forward end portion of a trailer; ahydraulic cylinder operative to extend the trailer engagement elementrelative to the support surface engagement element; a hydraulicaccumulator operatively coupled to supply pressurized hydraulic fluid tothe hydraulic cylinder, the hydraulic accumulator forming an on-board,self-contained energy source; an isolation valve fluidically interposingthe hydraulic cylinder and the hydraulic accumulator in a closedhydraulic system; a fifth wheel plate configured to selectively couplewith a fifth wheel of a tractor capable of towing the portable trailerstabilizer; and a valve operator mechanism configured to (i) open theisolation valve when the when the fifth wheel plate is coupled to thefifth wheel of the tractor, and (ii) shut the isolation valve when thefifth wheel plate is uncoupled from the fifth wheel of the tractor. 13.The portable trailer stabilizer of claim 12, wherein the valve operatormechanism comprises a valve operator element pivotable relative to thefifth wheel plate and operatively coupled to open and shut the isolationvalve.
 14. The portable trailer stabilizer of claim 13, wherein thevalve operator element is operatively connected to the isolation valveby at least one push rod.
 15. The portable trailer stabilizer of claim12, further comprising one or more wheels configured to support theportable trailer stabilizer on the support surface during repositioningof the portable trailer stabilizer by towing by the tractor.
 16. Aportable trailer stabilizer, comprising: a ground pad configured toselectively engage a support surface; a trailer engagement elementmovable relative to the ground pad, the trailer engagement elementconfigured to selectively engage a forward end portion of a trailer; astructural element supporting the trailer engagement element above thesurface engagement element; a closed hydraulic system containing ahydraulic fluid, the closed hydraulic system comprising a hydrauliccylinder operatively connecting the structural element and the trailerengagement element, the hydraulic cylinder configured to extend thetrailer engagement element relative to the support surface engagementelement, a hydraulic accumulator operatively coupled to the hydrauliccylinder, and an isolation valve fluidically interposing the hydrauliccylinder and the hydraulic accumulator; a positioning element engagementelement configured to selectively couple with a trailer stabilizerpositioning element of a tractor; and a valve operator mechanismconfigured to (i) open the isolation valve when the when the positioningelement engagement element is coupled to the trailer stabilizerpositioning element of the tractor, and (ii) shut the isolation valvewhen the positioning element engagement element is uncoupled from thetrailer stabilizer positioning element of the tractor.
 17. The portabletrailer stabilizer of claim 16, wherein the positioning elementengagement element comprises a channel configured to receive a portabletrailer stabilizer positioning element comprising an extended arm. 18.The portable trailer stabilizer of claim 16, wherein the positioningelement engagement element comprises two generally parallel channelsconfigured to receive respective generally parallel arms of the portabletrailer stabilizer positioning element.
 19. The portable trailerstabilizer of claim 16, wherein the positioning element engagementelement comprises a downwardly facing channel configured to receive aportable trailer stabilizer positioning element comprising an upwardlyfacing channel.
 20. The portable trailer stabilizer of claim 16, whereinthe positioning element engagement element comprises a bar configured toreceive a portable trailer stabilizer positioning element comprising ahook.
 21. The portable trailer stabilizer of claim 1, further comprisinga structural element operatively coupled to the support surfaceengagement element, the trailer engagement element, and the hydrauliccylinder; wherein the trailer engagement element is coupled to at leastone of the structural element and the hydraulic cylinder by a pivotconnection so that the trailer engagement element is tiltableside-to-side with respect to the trailer.
 22. The portable trailerstabilizer of claim 1, wherein the hydraulic fluid comprises one or moreof water, propylene glycol, a petroleum-based oil, and/or a syntheticoil.
 23. The portable trailer stabilizer of claim 1, wherein the supportsurface engagement element comprises a ground pad.
 24. The portabletrailer stabilizer of claim 1, further comprising at least one signalelement.
 25. The portable trailer stabilizer of claim 24, wherein thesignal element is configured to indicate whether the trailer engagementelement is fully extended relative to the support surface engagementelement.
 26. The portable trailer stabilizer of claim 24, wherein thesignal element is configured to indicate whether the isolation valve isshut.
 27. The portable trailer stabilizer of claim 4, wherein the valveoperator element is operatively connected to the isolation valve by acable.
 28. The portable trailer stabilizer of claim 4, wherein the valveoperator element is operatively connected to the isolation valve by apush rod.
 29. The portable trailer stabilizer of claim 5, wherein theportable trailer stabilizer positioning element is positioned at aforward end of the tractor.
 30. The portable trailer stabilizer of claim6, wherein the positioning element engagement element comprises twogenerally parallel channels configured to receive respective generallyparallel arms of the portable trailer stabilizer positioning element.